Process for the manufacture of shellac substitutes



Patented Sept. 19, 1933 UNITED STATES PROCESS FOR THE MANUFACTURE OFSHELLAC SUBSTITUTES Johannes Scheiber, Leipzig, Germany No Drawing.Application March 8, 1930, Serial No. 434,461, and in Germany November21,

6 Claims.

This specification is a continuation in part of the application filed byme on November 15, 1928, under Ser. No. 319,717 now Patent 1,903,598.

This invention relates to shellac substitutes and to processes formaking same.

The researches in the pure resin of natural shellac have shown that itsessential compounds are formed by lactid-like combinations ofaleuritinic-acid with shellol-acid or similar acids. Aieuritinic-acid isknown to be a trihydroxypalmitinic-acid, while shellol-acid is so far asknown a hydroaromatic hydroxycarboxylic acid. By heating mixtures ofthese two acids, resinlike products are formed which correspond in theiressential properties to the shellac resin itself.

A technical manufacture of shellac-like compounds as above outlined hasnot yet been effected. This has been attempted based upon the knowledgethat the combination of similar suitable products-such as aliphatichydroxyand polyhydroxycarboxylic acids of all kinds instead ofaleuritinic acid, and such as hydrogenized aromatic hydroxycarboxylicacids and oxidized resinolic-acids (for example hydroxy abietinicacid)instead of shellol-acid-produces resins which show essential features ofthe pure resin of shellac.

In carrying out this method practically the great disadvantage is thatthe production of suitable aliphatic or hydro-aromatic hydroxyandpolyhydroxycarboxylic acids presents great difliculties. Although-it iseasy to transform with a good yield castor-oil-(or ricinoleic)-acid intotrihydroxy-stearic-acid by treating castoroil-acid with a solution ofpermanganate by applying this method upon thecommerciallinseedoil-acids, there is produced a mixture of different unsaturatedaliphatic acids, not only a very poor yield of the correspondingpolyhydroxyacids, but moreover a mixture of inconstant and alwayschanging quality.

Furthermore the production of hydroaromatic hydroxycarboxylic acidsespecially suited for the said purpose is difficult or uneconomic or notuniform in quality, as for example the production of hydroxyresinolicacids by permanganatetreatment of resinolic acids, for instanceabietinic acid. Therefore, the choice of materials, from which to start,is very limited for both the groups of suitable hydroxyacids.

In my co-pending application, Ser. No. 319,717, flled November 15, 1928,it is stated that instead of using hydroxyand polyhydroxycarboxylicacids the corresponding halogenized derivatives discloses suchchlorinated products in combination with regularly obtained hydroxyorpolyhydroxycarboxylic acids, the present invention relates to combiningonly chlorinated or halogenized products. By this invention the choiceof suitable components for the resinification processes isextraordinarily enlarged.

There is no difficulty in chlorinating as well unsaturated aliphaticacids, especially the acids of drying oils as linseed-oil acids,poppy-seed-oil acids, etc. or of non-drying oils, as caster-oil acids,olive-oil acids, etc., as also suitable unsaturated hydroaromatic acids,especially the socalled resinolic-acids, as abietinic-acid,manilacopal-acids etc. The chlorination may be effected byintroducingchlorine into the liquefied or dissolved products, or byadding chlorine or a solutionof hypo-chlorite of soda to an alkalinesolution of the said acid-products, or in any other known and suitableway.

The chlorinated products may be precipitated from their watery alkalinesolutions by adding a dilute acid as for example hydrochloric acidimmediately or after some time, respectively after the solutions havebeen heated to accomplish the reaction, if necessary,'under pressure.Instead of separately chlorinating the two components it is alsopossible to chlorinate mixtures of unsaturated aliphatic acids withunsaturated hydroaromatic acids and to precipitate the chlorinatedproducts together.

These chlorinated substances, obtained in one way or another are to becombined with each other for the purpose of obtaining the desiredresin-products. This reaction can be easily effected by heating theproducts, hydrochloric acid being split off. It is sometimes advisableto add suitable catalyzers as finely dispersed metals, anhydrouschlorides, alkali, oxides or hydroxides of the alkaline earth-metals,carbonates, etc.

Inorder to more fully describe the present invention, I will now proceedto give some specific examples thereof, it being understood that I donot thereby intend to limit the invention to the particular proportions,combinations or ingredients given.

Example 1 50 parts of the mixture usually referred to as oflinseed-oil-acid" and 100 parts of Manilacopal are transformed into thecorresponding halogen derivates by introducing 40 parts of chlorine intotheir aqueous alkaline solution. The action of the chlorine beingfinished, dilute hydrochloric acid is added and the mixture of thechlorinated products is separated, washed and dried. The furthertreatment is-effected by heating the mixture preferably in the presenceof a small quantity of chloride of zinc. The temperature may be raisedat the end of the reaction until approximately 180 C. The resin obtainedshows especially well the peculiarities of natural shellac resin to bedissolved by weak alkalis, as borax, and to be aggregated by heat, ifthe temperature is kept for a short time at or above 200 C.

Example 2 120 parts of the mixture usually referred to ascastor-oil-acid" and 200 parts of Manila-copal are dissolved in water byadding 200 parts of carbonate of soda and heating preferably byintroducing steam. After cooling 92 parts of chlorine are added. Thechlorinated mixture is allowed to stand for some time and then heated ina vessel to about 150 C. After two hours the heating is stopped and thetemperature diminished to 70-80 C. for producing a good precipitationwhen adding hydrochloric acid. The precipitated mixture is washed, driedand then heated to a temperature of about 150 C. The resin thus producedis of extremely light colour and easily soluble in alcohol, butinsoluble in fatty oils, benzene and white spirit. It is, however,soluble in watery borax-solution. Furthermore it undergoes an extremelyquick change into an insoluble and unmeltable product by short heatingto temperatures at or above 200 C. All these properties show that thepresent resin resembles very closely the natural shellac resin itself.

Generally it is not diflicult to obtain the resinproducts, if preparedas described above, free of hydrochloric acid or of halogen, that splitsoff easily; in some cases however it may be advisable to grind theproduct with hot water, it being easily possible to obtain resins with ameltingpoint higher than 100 C. These products can be boiled out withwater without liability to conglutinate. If it seems advisable, smallquantities of an alkali metal carbonate or other alkali may be added tothe water.

The new products obtained are resins of lactidcharacter. They resembleperfectly the shellacresin itself and show especially the followingqualities: They are soluble in aliphatic alcohols and insoluble or butslightly soluble in hydrocarbons and fatty oils; they are easilypeptonized by weak alkalis. in particular by carbonates, ammonia andborax. They have a great ability of aggregation by heat. The quality ofthe resins can be changed in wide range for different purposes bysuitable additions, as waxes, natural and artificial resins of all kind,esters of cellulose, plastifying agents, etc.

I do not desire to limit my invention exactly to the details given, butto include any and all modifications within the scope of the appendedclaims.

I claim:

1. A process for the manufacture of shellac substitutes which comprisessubjecting a mixture of products obtained by the addition of halogen tounsaturated fatty acids from natural fatty oils and products obtained bythe addition of halogen to resinolic acids to the action of heat tillthe halogen has been split off and a shellaclike resin has been formed.

2. A process for the manufacture of shellac substitutes which comprisessubjecting a mixture of products obtained by the addition of chlorine tounsaturated fatty acids from natural fatty oils and products obtained bythe addition of chlorine to resinolic acids to the action of heat tillthe chlorine has been split off and a shellac-like resin has beenformed.

3. A process for the manufacture of shellac substitutes which compriseshalogenizing a mixture of unsaturated fatty acids from natural fattyoils and of resinolic acids, separating the mixture of the resultingreaction products and subjecting these products to the action of heattill the halogen has been split off and a shellac-like resin has beenformed.

4. A process for the manufacture of shellac substitutes which compriseschlorinating a mixture of unsaturated fatty acids from natural fattyoils and of resinolic acids, separating the mixture of the resultingreaction products and heating these products till the chlorine has beensplit off and a shellac-like resin has been formed.

5. A resin of lactid-character produced by subjecting to the action ofheat a mixture of products obtained by the addition of halogen tounsaturated fatty acids from natural fatty oils and products obtained bythe addition of halogen to resinolic acids till the halogen has beensplit off and a shellac-like resin has been formed.

6. A resin of lactid-character produced by subjecting to the action ofheat a mixture of products obtained by the addition of chlorine tounsaturated fatty acids from natural fatty oils and products obtained bythe addition of chlorine to resinolic acids till the chlorine has beensplit OH and a shellac-like resin has been formed.

JOHANNES SCHEIBER.

